2007 Yamaha Apex Factory Service Manual, Page 35Get this manual

2007 Yamaha Apex Factory Service Manual, Page 35

COMPRESSION PRESSURE MEASUREMENT CAUTION: INSP ADJ Before removing the spark plugs, use compressed air to blow away any dirt
few drops of oil into the affected cylinder and measure againRefer to the following tableCompression pressure (with oil applied
into cylinder) Reading Higher than without oil Diagnosis Piston ring(-s) wear or damageRepairPiston, valves, cylinder head
gasket or piston possibly defectiveRepairCompression pressure (at sea level) Same as without oil Compression pressure (at
sea level): Standard: 1,450 kPa (14.5 kgcm2, 206 psi) at 400 rmin Minimum: 1,260 kPa (12.6 kgcm2, 179 psi) at 400 rmin Maximum: